Herbal nutritional supplements are widely consumed by the public for their immune health properties. The most accepted method for analyzing these products that purportedly reflects their immune health properties is the ORAC value, which is a measure of total anti-oxidant activity. Though anti- oxidant activity is thought to have health benefits, including effects on the immune system, there is very little evidence of this benefit in vivo. Polyphenols are one of the major classes of compounds found in many nutritional supplements with anti-oxidant activity. We found that a subset of polyphenols, oligomeric procyanidins (OPCs), possess a unique capacity to enhance the immune system, distinct from anti-oxidant activity. Specifically, some polyphenols induce rapid induction of key immune cytokines that are critical to immune responses. Induction is due to enhanced transcriptional activity as well as enhanced transcript (mRNA) stability. This latter activity is absolutely unique. We developed a cell-based reporter assay for this activity, which we propose as a new screening tool for rating the immune-enhancing effects of nutritional supplements. This application application aims to improve upon this prototype bioassay by increasing the cell line robustness and identifying control standards. These studies will generate an optimized product for screening the immune activity of polyphenol-containing nutritional supplements.